The National Nuclear Security Administration (NNSA) plans to irradiate up to 5,000 tritium rods every 18 months using two Tennessee nuclear reactors, one of the seven options it was considering to meet national security requirements.
The semiautonomous Department of Energy branch said in a record of decision released Wednesday that it would implement its preferred alternative, which would involve tritium-producing burnable absorber rod (TPBAR) irradiation using the Watts Bar and Sequoyah nuclear reactor sites.
Tritium, a component of all the nuclear weapons in the U.S. stockpile, must be periodically replenished due to its short half-life.
According to the agency, although irradiation of 2,500 TPBARs over 18 months would be enough to meet near-term tritium requirements, manufacturing 5,000 TPBARs would better prepare the NNSA to meet future needs based on unexpected changes to its tritium requirements or events such as a prolonged reactor outage.
“The exact number of TPBARs to be irradiated during each/any 18-month reactor core cycle will be determined by both national security requirements and [Tennessee Valley Authority] reactor availability,” the decision said.
The agency could use up to four commercial light-water reactors between the two sites, each of which have two reactors. The agency chose this option to address the full range of tritium rods “that could, under any currently foreseeable circumstances, be irradiated in an 18-month period, at either or both the Watts Bar and Sequoyah sites, to satisfy national security requirements,” the decision said.
The other alternatives explored by NNSA in a March 2016 supplemental environmental impact statement on tritium production include the no-action option, which would involve irradiation of up to 2,040 TPBARs every 18 months; one option for irradiation of up to 2,500 TPBARs and another for up to 5,000 TPBARs only at the Watts Bar site; and two separate options for irradiation of those same amounts only at Sequoyah.
